Artificial leg



O. H. ERICKSON.

ARTIFICIAL LEG.

APPLICATION FILED Nov. 29, I920.

Patented J an. 31, 1922.

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APPLICATION FILED N0v.29, 1920.

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APPLICATION FILED NOV. 29, I920- 1,4()5,1 91 Patented Jan, 31, 1922.

3 SHEETS-SHEET 3- section by a knee joint. The invention is UNITED STATES ENT, CE-

o'r'ro I-I. ERICKSON, or MINNEAPOLIS, MINNESOTA.

ARTIFICIAL LEG.

Specification of Letters Patent.

Patented Jan. .31, 1922.

Application filed November 29, 1920. Serial No. 426,956.

. Legs; and I do hereby declarethe following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the'same;

This invention relates particularly to artificial legs of the type required for thigh amputations, and wherein 'the lower leg section is connected to the socket or upper leg directed chiefly to improved means for producing forward swinging movement of the lower leg section from the shoulder straps.

Generally stated, the invention consists of the novel devices and combinations of devices hereinafter'described' and defined in the claims. i

. 'In the accompanying drawings which illustrate the invention, like characters indicate like parts throughout theseveral views.

Referring to the drawings: 1 Fig. 1 is afront elevation of the improved le A Fig. 2 is a side elevation thereof;

Fig. 3 is, a vertical section showing the ankle pivotfor connecting the foot to the lower leg-section, said foot and lower leg section being indicated by dotted lines only;

Fig. 4 is an enlarged fragmentary vertical section'through the kneejoint; r

Fig. 5 shows the 10 er leg section and a portion of the socket or upper leg section chiefly .in rear elevation, but with some parts in section;?

. Fig. 6 is a section on theline 66 of Fig. 1; I Fig. 7 is'a section on the line 7-7 of Fig.

5, some parts being in full;

Fig. 8 is a side elevation illustrating a slightly modified arrangement of the legoperating connection, some parts being broken away; i

inFig. 8, but with some parts sectioned and -Wlth the thigh socket removed from the con- :nection with the knee block; and

Fig. 10 is a front elevation of the knee f block and thigh socket shown in Fig. 8, some parts of the latter being broken away. 3 The lower leg section is provided with a foot 12 pivot-allyconnected-thereto by any suitable means, and 7, wherein the numeral 13indicates a tubular pivot' sleeve provided with nutequlpped stems 14 that anchor it to the lower such as shown inzFigs. 3

leg section- The numeral 15 indicates a nut-equipped stem. or bolt that is anchored central portion of the stem 14. The numeral 16 indicates coiled compression to the foot 12, and hasv an eyepivoted on the spring seated in recesses inthe lower portion of'the legsection 11 and in the'heel of the .foot 12, screw 17 that works through a nut 18 an chored in the foot.

and adapted to be adjusted by a Thespring 16 tends to rock the toe of the i foot 'up, and this movement is adjustably limited by a stop screw 19' that works through a nut 20 anchored in the lower front portionzof the leg section 11 and impinging on a small bearing plate 21 on the recessed top portion of the foot. By adjustments of the stop screw 19, the upward movement of the toe o'f'the foot may be variably limited so as to give the right walking action for the particular plied. I

Thelower leg section 11, except at its'lowermost portion, is hollow, and at the extreme upper portion of its sides, it is provided personto whom the leg is apwith rigidly secured hinge straps 22 through which is passed a tubular knee joint. pivot .bolt 23, that is headed at onccnd and pro "vidcd with a cap-screw 24 at its other end.

The ithighsoeket or upper leg section25 is provided at its lower end with a knee block 26 that is pivoted 'onthe knee joint pivot bolt 23, and, as shown, is provided with an inset metal bushing27 that directly engages the'same. The lowerportion of the knee block projects'down into the upper end Y of the lower edge section .11 and this block is provided with: a". vertical slot 28. The

pivoted portion of the block 26' is considerably narrower than the sp'acebetween .the

hinge straps 22, so as to l'eave space for its;

laterally spaced pairs of cordguide'sheaves 29 and '30 that are loosely journaled on'the I Fig. 9 is a front elevation of the leg shown end portions of the pivot bolt 23 just inward of said straps 22. I

The numer 'l 31 indicates anon-elastic but flexible stop cord or strap, the upper end of which works in the slot 28, of the knee block stop cord 31* extends downward into; the

lower leg section 11 and is secured to the yoke of a U-bolt 33, which, in turn, is ex-.

tended through an anchor bar or lug 34 on the rear portion of said leg section 11, and v is made adjustable by a nut 35. By adjustments of the nut 35, the anchor bolt 33 may be adjusted so as to cause the stop cord or strap 31 to limit the forward swinging shown as of the type disclosed and claimed in iny prior Patent No. 1,302,336, of date, April 29, 1919 and wherein the thigh socket 25 is adjustably connected to the knee block 26 by threaded engagement at 25 (see particularly Fig. 9).

The customary shoulder straps 36 are attached to shoulder'strap cords 37 located, one on each side of the leg. lower portions of these cords 37 extend down on'the upper sides of the thigh socket 25, and thence, through guide sheaves 38, in the kneebl-ock 26, to the interior of the lower leg section 11, where they are passed under grooved guide sheaves 39: journaled tobrackets 40 located, one on. each side of the interior of the lower leg section. The two upwardly extended branches of each cord 37 extend one over each of the guide sheaves 29 and 30. The cords 37 are adapted to work through guide loops l1 on the upper portion of the thigh socket 25.

The construction illu trated in Figs. 8, 9 and 10 is like that already described, except for the fact that the guide sheaves 29 and 30, which correspond to the guide sheaves 29 and 30 of the previously described arpartly by rangement, are journaled in pairs, one ahead of the other, 'on the opposite sides ofthe knee block 26, and except, also, for the further fact that the above described stop cord or strap 31 and its adjustable anchor bolts are arranged in duplicate.

It will, of course, be understood that in the buckling action the forward swinging movement of the lower edge section is produced gravity, but chiefly by upward strain. on the shoulder straps 36. and cords 37. Inasmuch as the cords 37 run against the-front portions of the guide sheaves 29 and 30, it is evident that the pull on the cords, being forward of the axis of the pivot bolts 23 will produce the said forward swinging movement ofthe lower leg section, and as the cords run over the said sheaves independently,-the friction on the pulling action will be reduced to a minimum. Moreover, by running the cords down through the knee block intoithe interior of the lower leg section, they are protected so that they will not catch underwear and their move- The looped ments will not'be interfered with by outside exterior of said upper leg section, extended over the guide sheaves on said upper leg section intothe lower leg section and under the guide sheaves on the 1nter1or of said lower leg sectlon, said guide cord operatmg on said sheaves to produce a forward swing mg movement of said lower leg section.

with upper: and lowerleg sections pivotally connectedby a kneejoint, guide sheaves on the lower portion ofsaid upper leg section and on the interiorof said lower leg section, shoulder straps and cords guided on the exterior of said upper leg section, extended over the guide sheaves on said upper leg section and under the guide sheaves on the interior of said lower leg section, said guide cord operating on said sheaves to produce 'a forward swinging movement of said lower leg section, and a stop strap conne'cting'said upper and lower leg sections at the rear of the knee joint.

3. In an artificial leg, the combination with upper and lower leg sections, the former having a knee block, a knee oint pivot bolt connecting said lower leg section to said knee block, guide sheaves on the interior of said lower'leg section, guide sheaves on 2. In an artificial leg, the combination,

said knee block having portions that are 7 forward of the axis of the *kneejoint, and shoulder straps and cords, the latter extending from the exterior of said upper leg section, through joints in said knee block over the sheaves on said knee block and 'under the sheaves on the interior-of said lower leg section.

4:. An artificial leg comprising upper and section, and shoulder strapsand cords, the

latter extending from the exterior of said upper leg section, through joints on said knee block, over the sheaves on said pivot bolt, and under the sheaves on the interior of said lower leg section.

5. In an artificial leg, the combination with upper and lower legsections, the former having a knee block pivotally connected to said lower leg section by a knee joint pivot, guide sheaves on said knee block, 1 and shoulder strap cords extended through 10 guides on said knee block and over the guide sheaves thereon and acting on the lower leg section to swing the same forward under upward strain on said cord.

In testimony whereof I aflix OTTO H. ER

HIE CSI nature. 15

SON. 

